Copper · Maryland

Copper in Maryland Drinking Water — 16 ZIPs Tested

EPA data analysis for copper in Maryland drinking water systems

16
ZIPs with Detections
15
ZIPs with Violations
2.4%
Violation Rate
1.3 mg/L (action level)
EPA Limit
Moderate
Health Risk
Reverse Osmosis or NSF 53 Carbon Block
Best Filter Method

Copper Contamination in Maryland

ZipCheckup analyzed drinking water data across 615 ZIP codes in Maryland for copper contamination. 16 ZIP codes have reported copper detections, and 15 have EPA violations on record.

The violation rate for copper in Maryland is 2.4% of all ZIP codes — roughly in line with the national average.

EPA Standard for Copper

The EPA maximum contaminant level (MCL) for copper is 1.3 mg/L (action level), governed by the Lead and Copper Rule. Water systems that exceed this limit must take corrective action and notify consumers.

Worst ZIP Codes for Copper in Maryland

These ZIP codes reported the highest copper levels in Maryland based on CCR reports and EPA data:

Lowest Copper Levels in Maryland

These ZIP codes had the lowest reported copper detections in Maryland:

Health Effects of Copper

Short-term exposure to copper above the action level causes gastrointestinal distress (nausea, vomiting, diarrhea). Long-term exposure can cause liver and kidney damage. People with Wilson's disease are particularly sensitive.

How to Remove Copper From Drinking Water

The most effective treatment for copper removal is Reverse Osmosis or NSF 53 Carbon Block. Look for filters certified under NSF 53 standards.

Check Your ZIP Code

Use the ZipCheckup water quality search to see copper data for your specific water system in Maryland.

Worst ZIP Codes for Copper in Maryland

Ranked by highest copper detection level.

Rank ZIP Code City Level Detected EPA Limit Status
1 21917 Colora 4950 ppb 1300 ppb Exceeds
2 21660 Ridgely 1900 ppb 1300 ppb Exceeds
3 21682 Ridgely 1900 ppb 1300 ppb Exceeds
4 21683 Ridgely 1900 ppb 1300 ppb Exceeds
5 21688 Ridgely 1900 ppb 1300 ppb Exceeds
6 21041 Ellicott City 1780 ppb 1300 ppb Exceeds
7 21042 Ellicott City 1780 ppb 1300 ppb Exceeds
8 21043 Ellicott City 1780 ppb 1300 ppb Exceeds
9 21048 Finksburg 1700 ppb 1300 ppb Exceeds
10 21153 Stevenson 1690 ppb 1300 ppb Exceeds
11 21154 Street 1600 ppb 1300 ppb Exceeds
12 21645 Kennedyville 1420 ppb 1300 ppb Exceeds
13 20854 Potomac 1400 ppb 1300 ppb Exceeds
14 20859 Potomac 1400 ppb 1300 ppb Exceeds
15 20754 Dunkirk 1390 ppb 1300 ppb Exceeds
16 21719 Cascade 1.25 ppm 1.3 ppm Within Limit

Lowest Copper Levels in Maryland

ZIP Code City Level Detected
21719 Cascade 1.25 ppm
20754 Dunkirk 1390 ppb
20859 Potomac 1400 ppb
20854 Potomac 1400 ppb
21645 Kennedyville 1420 ppb
21154 Street 1600 ppb
21153 Stevenson 1690 ppb
21048 Finksburg 1700 ppb
21043 Ellicott City 1780 ppb
21042 Ellicott City 1780 ppb

Cities with Copper Data in Maryland

5 cities in Maryland have copper testing data available.

Maryland Water Quality Overview: See statewide water quality rankings on the Maryland water quality page.
Learn more about Copper: Read the full guide on Copper in drinking water.
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